A 1500 kW, 600 V, 16 pole, dc generator runs at 200 rpm.There are 2500 lap connected conductors and full load copper losses are 25kW. Average air gap flux density is 0.85T. The area of the pole shoes is_____ cm2 (Neglect field current)
861
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Solution
The correct option is A 861 Full load armature current, Ia=1500×1000600=2500A
copper-loss=I2aRa=25×1000=25kW
where Ra is the effective resistance of the armature circuit,
Ra=25×10002500×2500=4×10−3Ω
Induced emf, Ea=Vt+IaRa =600+2500×4×10−3=610V
Also, Ea=(ϕNZ60)(PA)
⇒610=ϕ×200×250060×(1616) (for lap connected A = P)